Food Resources

Chapter 13

We’re not in Kansas anymore

New technology for Kansas PrairiesPolyculture

– Plant perennial grasses– Legumes (return nitrogen to the soil)– Sunflowers– Grain crops– Plants that provide natural pesticide

This makes Toto very happy

Perennial polyculture blended with monoculture helps in the following way

Less plowing – lower soil erosionLess pollution from pesticide use/fertilizerLess need for irrigation (deep root

systems)

How is the world fed?

Cropland (produce grain mostly)Rangeland (livestock)Oceanic fisheries

Food production has increased to keep up with the growing population

Machines,inorganic fertilizers,irrigation, pesticides, high-yield varieties of wheat/rice, increased density in feedlots, aquaculture

What are the implications of increased food production

Environmental degradation– Soil loss, lost habitat, contaminated water

Pollution – nitrogen, phosphates, pesticidesLack of water – diminishing water tableOvergrazing – reducing grassland

productivityOverfishing – reducing fish stocks (?)Loss of ecological services

What do we really eat

(other than McDonalds, of course)15 plants and 8 animals make up 90% of the food

we consumeBig 3 grains – wheat, rice, cornBig 3 meats – beef, pork, chickenFish – important food source for more than a

billion people

What, no tofurkey?

Types of Agriculture

Industrialized or high input– Uses high amounts of:– fossil fuel energy– Water– Commercial inorganic fertilizer– Pesticide use– monocultures

Types of Ag continued

Plantation Agriculture (a variety of industrial)– In tropical areas– Growing cash crops (tobacco, coffee,

sugarcane, cocoa, bananas, soybeans)

Types of Ag continued

Traditional Subsistence Ag– Uses mostly human and animal labor– Low use of inorganic fertilizer– Low pesticide use– Usually food for family only, small surplus– Includes shifting cultivation in tropical areas

and nomadic livestock

Types of Ag continued

Traditional Intensive Ag– High labor– High fertilizer/pesticide use– High yield (able to sell for profit)

– Typical of rice production

Green Revolution

High input monocultures to the rescue?

Three steps– Developing high yield monocultures– Using large inputs of fertilizer/pesticide/water– Increase the frequency and density of farming

First green revolution –US and EuropeSecond green revolution – Tropical areas especially rice

in Asia

The US and Food

With only 0.3% of the farm labor force, the US produces 17% of the worlds grain

US spends only about 10-12% of their income on food (18% Japan, 40-70% developing countries)

In the US it takes 10 units of fossil fuel to produce 1 unit of food ( as compared to intensive which takes 1 unit to produce 10)

Growing Techniques

Monoculture – only one plant type Interplanting – several monocultures on one plot

of land (including)– Polyvarietal cultivation – several varieties of the same

plant

– Intercropping – two or more plant types grown at the same time

– Alley cropping – plants and trees together

– Polyculture – several types of plants on one plot at one time harvested at different times usually

Increase in food production

Since 1950 grain production has tripledAverage food price dropped 25%Food traded worldwide quadrupledMeat production has risen for 41 years

Problems with production

Areas with 2 billion (sub-Saharan Africa) growth is surpassing food production

Grain production has leveled off– Limits to irrigation, fertilizer, pesticide– Loss of topsoil, agricultural land, and

salinization of the soil

Nutrition

Nutrition affects life expectancy, disease resilience, and life quality

Undernutrition – do not get enough foodMalnutrition – do not get enough key nutrients

(vitamins and minerals)

WHO says that 10 million die annually (most under 5) from poor nutrition and diseases associated with it

Effects of Food Production

Biodiversity loss – clearing land, pesticide runoff, lack of predators

Soil degradation- erosion, loss of fertility, salinization, desertification

Air pollution- fossil fuel emissions, dustWater- sediment, fertilizers, pesticides,

aquifer depletion, increased runoffHuman Health- nitrates in water,

pesticides, bacterial contamination of meat

GMO

Genetically Modified Organisms

Faster than crossbreeding, less costly, unlimited combination

Nearly 2/3 of US food in supermarkets contains GMO’s

Do not know all the long term effects on the environment

Meat Production

Rangeland – 40% of the planet’s ice free land, mostly grasslands

Pasture – managed grasslands and meadows, often irrigated, normally fenced

Rangeland plants- anchor soil, extract deep water (survive drought), store nutrients

Most grasses can have the top eaten and grow back easily

Problems with meat production

Concentrated production facilities – Foul odor, water pollution (wastes) (+ aquifer)

Overgrazing– Lower productivity of grasses– Reduces plant cover (soil erosion wind/water)– Compacts soil– Increase amount of woody shrubs– Major cause of desertification

Pesticide and pest control

Do you know

What are the problems with pesticide?

What are the different types of pesticide?

When should pesticides be used?

How are pesticides part of a negative feedback loop?

Pesticide problems

Kills many other organisms

Only about 2% reaches target species

Kills genetically weak species, strengthening the species overall

Often the toxin has a long life span

Creates birth defects

Kills natural predators

Types of pesticideHerbicides – weed killersFungicides – fungus killersNematocides – worm killersRodenticides – rat and mouse killers

DDT – first of the second generation pesticides and world’s most used pesticide in 1948. In the US most pesticide is used on corn and cotton (90% of insecticide and 80% herbicide)

Pros for pesticide

Human lives are saved by killing disease carrying pests (mosquitoes)

Increased food supply

Increased profit for farmers

Pesticides work quickly to remove pests

When used appropriately the health risk to humans is low compared to the benefit (ACSH)

Pesticide info

InsecticideChlorinated hydrocarbons – DDT, aldrin, diedrin, chlordane, toxaphene, mirex

These are the bad ones

Long lasting

Biologically magnified

Pesticide info continuedMost other types of pesticide are relatively safe – low persistence (up to a few weeks) and are not biologically magnified

Organophosphates – malathion, DDVP

Carbamates – aldicarb

Botanicals – extracted from plants

Micro botanicals – fungi, bacteria, protozoa

Synthetics – “lasso,” “roundup”

Bad types continued

Fumigants are generally bad. Not only do they last a long time, and biomagnify, they often are spread vast distances with the wind

Carbon tetrachlorideEthylene dibromideMethyl bromide

Positive feedback loop

Pesticides increase genetic resistance making bugs stronger each generation

Natural predators are also killed

New pest populations can explode when predators are killed

Leads to pesticide treadmill – having to use more and more pesticide to kill the pests because of the feedback loop

First pesticide awareness

Rachel Carson – Silent Spring, opened the publics’ eyes to the danger of pesticide.

Linked birth defect rise in population back to pesticide use.

The real problems

Pesticides linger in the air and on foods

Workers are exposed to high levels

Animals are exposed to toxins while pregnant

Tolerance levels are not set based upon health concerns, but upon crop concerns

There is little enforcement of use of pesticides